Assessing an intuitive condition for stability under a range of traffic conditions via a generalised Lu-Kumar network

We argue the importance both of developing simple sufficientconditions for the stability of general multiclass queueing networks and also of assessing such conditions under a range of assumptions on the weight of the traffic flowing between service stations. To achieve the former, we review a peak-rate stability condition and extend its range of application and for the latter, we introduce a generalisation of the Lu-Kumar network on which the stability condition may be tested for a range of traffic configurations. The peak-rate condition is close to exact when the between-station traffic is light, but degrades as this traffic increases.

The influence of environmental conditions on immune responses, morphology and recapture probability of nestling house martins (Delichon urbica)

Nestling birds produced later in the season are hypothesized to be of poor quality with a low probability of survival and recruitment. In a Spanish population of house martins (Delichon urbica), we first compared reproductive success, immune responses and morphological traits between the first and the second broods. Second, we investigated the effects of an ectoparasite treatment and breeding date on the recapture rate the following year. Due probably to a reverse situation in weather conditions during the experiment, with more rain during rearing of the first brood, nestlings reared during the second brood were in better condition and had stronger immune responses compared with nestlings from the first brood. Contrary to other findings on house martins, we found a similar recapture rate for chicks reared during the first and the second brood. Furthermore, ectoparasitic house martin bugs had no significant effect on the recapture rate. Recaptured birds had similar morphology but higher immunoglobulin levels when nestlings compared with non-recaptured birds. This result implies that a measure of immune function is a better predictor of survival than body condition per se.

Development of the immature stages of Culex (Culex) saltanensis Dyar (Diptera, Culicidae) under laboratory conditions

Development of the immature stages of Culex (Culex) saltanensis Dyar (Diptera, Culicidae) under laboratory conditions. Culex (Culex) saltanensis Dyar, 1928 is becoming frequent and abundant in natural and artificial breeding sites in urban and rural areas of Brazil. This study contributes to the knowledge of the biology of a Brazilian strain of C. saltanensis. The development of specimens reared individually or grouped was observed. The study was conducted at a constant temperature of 27 ± 2°C, 14L:10D photoperiod and 80 ± 5% relative humidity. The immature stages were observed every 6 hours until adult emergence, which occurred in 12.29 days among individually reared specimens and in 13.12 days among group-reared specimens. Egg rafts for the experiment were obtained from the laboratory and field. Eggs hatched at a rate of 97.48 ± 2.32%. More eggs per egg raft were obtained from the field than from the laboratory. Males from individually reared specimens emerged in 12.29 ± 1.11 days and females in 13.12 ± 1.58 days. The male-female ratio was 1:1. Larval survival rate was higher than 85% for larvae reared isolated and higher than 95% for group-reared larvae. The Culex saltanensis life cycle was completed within 12 to 14 days, where larval instars I and IV took the most time to develop and the pupae, the shortest.

Interpretation of paleoceanographic conditions on the Peru shelf using paleoecology and geochemistry

Analisa una serie de sedimentos geoquimicos de nueve muestras colectadas a lo largo del recorrido de Panamá.

Phenology of Spalangia endius Walker (Hymenoptera, Pteromalidae) in pupae of Musca domestica Linnaeus (Diptera, Muscidae) under laboratory conditions

This work describes the phenology of Spalangia endius Walker in pupae of Musca domestica Linnaeus under laboratory conditions. In order to understand the developmental cycle of Spalangia endius under laboratory conditions, 360 Musca domestica pupae aged from 24 to 48 hours were exposed to 15 S. endius pairs for a period of 24 hours at 26 ± 2ºC. These pupae were kept in a BOD incubator at the same temperature, with a relative humidity of <70%, and 12 hours photophase. Fifteen hymenopteran specimens were dissected daily to evaluate their stage and development time. The phenology concluded that S. endius had a development cycle of 19 days with an incubation period of 24 hours. The development of the larvae of S. endius occurred in the subsequent eight days, during which a series of morphological alterations were observed. The pre-pupal stage occurred on the tenth day, where the movement ceased and elimination of the meconium started. The pupal stage occurred from the 11th to the 19th day, with emergence of males first, followed by female emergence approximately 24 hours later. These results allowed the evaluation of aspects of the detailed bionomics of the development of S. endius in order to record and program production of this parasitoid, thus optimizing its utilization as a biological control agent.

Comparative testing of a miniature diffusion size classifier to assess airborne ultrafine particles under field conditions

Miniature diffusion size classifiers (miniDiSC) are novel handheld devices to measure ultrafine particles (UFP). UFP have been linked to the development of cardiovascular and pulmonary diseases; thus, detection and quantification of these particles are important for evaluating their potential health hazards. As part of the UFP exposure assessments of highwaymaintenance workers in western Switzerland, we compared a miniDiSC with a portable condensation particle counter (P-TRAK). In addition, we performed stationary measurements with a miniDiSC and a scanning mobility particle sizer (SMPS) at a site immediately adjacent to a highway. Measurements with miniDiSC and P-TRAK correlated well (correlation of r = 0.84) but average particle numbers of the miniDiSC were 30%âeuro"60% higher. This difference was significantly increased for mean particle diameters below 40 nm. The correlation between theminiDiSC and the SMPSduring stationary measurements was very high (r = 0.98) although particle numbers from the miniDiSC were 30% lower. Differences between the three devices were attributed to the different cutoff diameters for detection. Correction for this size dependent effect led to very similar results across all counters.We did not observe any significant influence of other particle characteristics. Our results suggest that the miniDiSC provides accurate particle number concentrations and geometric mean diameters at traffic-influenced sites, making it a useful tool for personal exposure assessment in such settings.

Extra burden of psychosomatic complaints among adolescents suffering from chronic conditions.

OBJECTIVE:: To determine whether there are differences in health perception and health care use among adolescents with psychosomatic symptoms (PS), with chronic conditions (CCs), and with both conditions compared with healthy controls. METHODS:: By using the SMASH02 database, 4 groups were created: youths with PS but no CCs (N = 1010); youths with CCs but no PS (N = 497); youths with both psychosomatic symptoms and chronic conditions (PSCC, N = 213); and youths with neither PS nor CC (control, N = 5709). We used χ tests and analysis of variance to compare each variable between the 4 groups. In a second step, all health and health care use variables were included in a multinomial regression analysis controlling for significant (p < .05) background variables and using the control group as the reference. RESULTS:: Overall, PS and PSCC youths were significantly more likely to rate their health as poor, to be depressed, and to have consulted several times their primary health care provider or a mental health professional than their healthy peers. With the exception of being depressed, PSCC adolescents reported worse health perception and higher health care use than CC and PS. CONCLUSIONS:: Although PS youths do not define PS as a CC, it should be considered as one. Moreover, having PS represents an additional burden to chronically ill adolescents. Health professionals dealing with adolescents must be aware of the deleterious health effects that PS can have on adolescents and have this diagnosis in mind to better target the treatment and improve their management.

Bioactivity of the latex from Parahancornia amapa (Apocynaceae) on the development of Rhodnius nasutus (Hemiptera, Reduviidae, Triatominae) under laboratory conditions

Bioactivity of the latex from Parahancornia amapa (Apocynaceae) on the development of Rhodnius nasutus (Hemiptera, Reduviidae, Triatominae) under laboratory conditions. The aim of this study was to verify the effects of the methanolic fraction of the latex from Parahancornia amapa (Apocynaceae) (PALAM) on individuals of the species Rhodnius nasutus Stål (Hemiptera, Triatominae). Many of the insects treated with the substance presented deformities and these may interfere in the feeding and possibly hinder the reproductive capacity. They also presented significant mortality during the molt when compared to the control group, noting a gradual increase in mortality. The treated insects also presented delayed nymphal development (5th instar) and higher adult longevity.

Biological aspects of immature stage of Nyssomyia whitmani (Antunes and Coutinho) (Diptera, Psychodidae, Phlebotominae) in laboratory conditions

Nyssomyia whitmani (Antunes and Coutinho, 1939) has been considered as a complex of cryptic species, and some of the populations of this complex plays an important role in the transmission of Leishmania spp. in Brazil. The present study reports the biological aspects concerning the productivity out of eggs and the development time of the descendants of females obtained in Dourados municipality, Mato Grosso do Sul state. The females were captured with modified electric aspirators, fed in hamsters and further individualized in containers for breeding. At the insectary, temperature and relative humidity were maintained on average of 24.5 °C and 67.3%, respectively. From 944 females 3737 eggs were obtained, 748 (20.0%) evolved to the stage of larvae, and 93 (12.4%) of these reached adult stage. The life cycle lasted 80.6 days and the last larval instar was the longest. The use of a higher protein diet revealed a significant improvement in larval development.

Characterization of Human Late Outgrowth Endothelial Progenitor-Derived Cells under Various Flow Conditions.

Background: Endothelial progenitor-derived cells (EPC) are a cell therapy tool in peripheral arterial disease and for re-endothelialization of bypasses and stents. Objective: To assess EPC behavior under flow conditions normally found in vivo. Results: EPC were isolated from human cord blood, cultured on compliant tubes and exposed in an in vitro flow system mimicking hemodynamic environments normally found in medium and large arteries. EPC exposed for 24 h to unidirectional (0.3 ± 0.1 or 6 ± 3 dynes/cm(2)) shear stress oriented along flow direction, while those exposed to bidirectional shear stress (0.3 ± 3 dynes/cm(2)) or static conditions had random orientation. Under bidirectional flow, tissue factor (TF) activity and mRNA expression were significantly increased (2.5- and 7.0-fold) compared to static conditions. Under low shear unidirectional flow TF mRNA increased 4.9 ± 0.5-fold. Similar flow-induced increases were observed for TF in mature umbilical vein-derived endothelial cells. Expression of tissue-type plasminogen activator (t-PA), urokinase (u-PA) and monocyte chemotactic protein 1 (MCP1) were reduced by 40-60% in late outgrowth endothelial progenitor-derived cells (LO-EPC) exposed to any flow environment, while MCP1, but not t-PA or u-PA, was decreased in HUVEC. Conclusions: Flow, in particular bidirectional, modifies the hemostatic balance in LO-EPC with increased TF and decreased plasminogen activator expression.

Are adolescents with chronic conditions particularly at risk for bullying?

OBJECTIVE: To compare the prevalence and intensity of victimization from bullying, and the characteristics of the victims of bullying, comparing adolescents with and without chronic conditions. DESIGN: School survey. SETTING: Post-mandatory schools. PARTICIPANTS: A total of 7005 students (48% females) aged 16-20 years, distributed into adolescents with chronic conditions (728, 50% females) and controls (6277, 48% females). Chronic condition was defined as having a chronic disease and/or a physical disability.OUTCOME MEASURES: Prevalence of bullying; intensity of bullying; and socio-demographic, bio-psychosocial, familial, school, and violence context characteristics of the victims of bullying. RESULTS: The prevalence of bullying in our sample was 13.85%. Adolescents with chronic conditions were more likely to be victims of bullying (Adjusted Odds Ratio [AOR] 1.53), and to be victims of two or three forms of bullying (AOR 1.92). Victims of bullying with chronic conditions were more likely than non-victims to be depressed (Relative Risk Ratio [RRR] 1.57), to have more physical symptoms (RRR 1.61), to have a poorer relationship with their parents (RRR 1.33), to have a poorer school climate (RRR 1.60), and to have been victims of sexual abuse (RRR 1.79) or other forms of violence (RRR 1.80). Although these characteristics apply to victims in general, in most cases they are less pronounced among victims without chronic conditions. CONCLUSIONS: Chronic conditions seem to be a risk factor for victimization from bullying. Therefore, as adolescents with chronic conditions are increasingly mainstreamed, schools should be encouraged to undertake preventive measures to avoid victimization of such adolescents.

Registries in rheumatological and musculoskeletal conditions. Paediatric Behçet's disease: an international cohort study of 110 patients. One-year follow-up data.

OBJECTIVE: To set-up an international cohort of patients suspected with Behçet's disease (BD). The cohort is aimed at defining an algorithm for definition of the disease in children. METHODS: International experts have defined the inclusion criteria as follows: recurrent oral aphthosis (ROA) plus one of following-genital ulceration, erythema nodosum, folliculitis, pustulous/acneiform lesions, positive pathergy test, uveitis, venous/arterial thrombosis and family history of BD. Onset of disease is <16 years, disease duration is ≤3 years, future follow-up duration is ≥4 years and informed consent is obtained. The expert committee has classified the included patients into: definite paediatric BD (PED-BD), probable PED-BD and no PED-BD. Statistical analysis is performed to compare the three groups of patients. Centres document their patients into a single database. RESULTS: At January 2010, 110 patients (56 males/54 females) have been included. Mean age at first symptom: 8.1 years (median 8.2 years). At inclusion, 38% had only one symptom associated with ROA, 31% had two and 31% had three or more symptoms. A total of 106 first evaluations have been done. Seventeen patients underwent the first-year evaluation, and 36 had no new symptoms, 12 had one and 9 had two. Experts have examined 48 files and classified 30 as definite and 18 as probable. Twenty-six patients classified as definite fulfilled the International Study Group criteria. Seventeen patients classified as probable did not meet the international criteria. CONCLUSION: The expert committee has classified the majority of patients in the BD group although they presented with few symptoms independently of BD classification criteria.

Persistence and cell culturability of biocontrol strain Pseudomonas fluorescens CHA0 under plough pan conditions in soil and influence of the anaerobic regulator gene anr.

Certain fluorescent pseudomonads can protect plants from soil-borne pathogens, and it is important to understand how these biocontrol agents survive in soil. The persistence of the biocontrol strain Pseudomonas fluorescens CHA0-Rif under plough pan conditions was assessed in non-sterile soil microcosms by counting total cells (immunofluorescence microscopy), intact cells (BacLight membrane permeability test), viable cells (Kogure's substrate-responsiveness test) and culturable cells (colony counts on selective plates) of the inoculant. Viable but non-culturable cells of CHA0-Rif (106 cells g-1 soil) were found in flooded microcosms amended with fermentable organic matter, in which the soil redox potential was low (plough pan conditions), in agreement with previous observations of plough pan samples from a field inoculated with CHA0-Rif. However, viable but non-culturable cells were not found in unamended flooded, amended unflooded or unamended unflooded (i.e. control) microcosms, suggesting that such cells resulted from exposure of CHA0-Rif to a combination of low redox potential and oxygen limitation in soil. CHA0-Rif is strictly aerobic. Its anaerobic regulator ANR is activated by low oxygen concentrations and it controls production of the biocontrol metabolite hydrogen cyanide under microaerophilic conditions. Under plough pan conditions, an anr-deficient mutant of CHA0-Rif and its complemented derivative displayed the same persistence pattern as CHA0-Rif, indicating that anr was not implicated in the formation of viable but non-culturable cells of this strain at the plough pan.